A deep foundation pit excavation supporting structure for deep sandy soil

Abstract

The application relates to the technical field of foundation pit supporting equipment, in particular to a deep foundation pit excavation supporting structure for deep thick sandy soil, which comprises steel supporting plates used for excavating and supporting deep thick sandy soil deep foundation pits, the cross section of the steel supporting plates is trapezoidal, two horizontally-symmetrical steel supporting plates are combined into a supporting piece, symmetrical horizontal plates are arranged at the inner concave side bevels of the steel supporting plates, a positioning protruding block is fixedly arranged at one end of the steel supporting plate, and a positioning recess is arranged at the other end of the steel supporting plate; supporting sliding blocks are inserted into the gaps of the two horizontal plates in the same supporting piece, square tubes are welded to the side walls of the two supporting sliding blocks, square blocks are inserted into the interiors of the square tubes, positioning sleeves are welded between the two square blocks of the same supporting piece, a fixing assembly is arranged in the interior of the positioning sleeve, at least one positioning groove is arranged at the top of the square block, and a bolt is inserted into the interior of the positioning groove in a matched mode, the application can be quickly vertically inserted into the interior of the sandy soil, the construction inclination state cannot appear, and the application has the characteristics of high supporting stability.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support equipment technology, specifically a deep foundation pit excavation support structure for deep sandy soil. Background Technology

[0002] An excavation pit is a pit dug at the foundation design location according to the base elevation and foundation plan dimensions. Before excavation, an excavation plan should be determined based on geological and hydrological data, combined with the situation of nearby buildings, and waterproofing and drainage work should be carried out. For shallow excavations, slope protection can be used to stabilize the soil slope, and the slope should be determined according to relevant construction regulations. For deeper excavations or those near nearby buildings, foundation pit wall support methods can be used.

[0003] The main support methods for foundation pits include anchored bracing, cast-in-place pile support for retaining walls, and temporary retaining wall support. These methods are mainly suitable for excavating relatively large foundation pits with low groundwater levels and shallow depths, or when mechanical excavation is used and horizontal bracing cannot be installed. When the foundation pit is deep, the soil is sandy, the groundwater level is high, and dewatering has not been carried out, sheet piles are used as the support structure, which can retain soil, prevent waterlogging, and prevent quicksand. Sheet pile support can be divided into anchorless sheet piles and anchored sheet piles. Commonly used steel sheet piles are a type of sheet pile. The construction method generally uses mechanical driving of each sheet pile one corner at a time. Each sheet pile is driven continuously from start to finish, which is simple and fast. However, each sheet pile is prone to tilting to one side, causing the sheet pile support angle to tilt, resulting in a generally poor overall support effect. At the same time, when the foundation pit is excavated after the sheet piles are driven into the ground, there is a lack of support on the inside of the sheet piles, resulting in insufficient overall stability of the sheet pile support. Summary of the Invention

[0004] In view of the problems in the prior art, where single sheet piles tend to tilt to one side when driven, resulting in an inclination of the sheet pile support angle and thus a generally poor overall support effect, and where the lack of support on the inner side of the sheet piles during foundation pit excavation after the sheet piles are driven into the soil leads to insufficient overall stability of the sheet pile support, this invention provides a deep foundation pit excavation support structure for deep sandy soils.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a deep foundation pit excavation support structure for deep sandy soil, including a steel support plate for excavating and supporting a deep foundation pit for deep sandy soil. The cross section of the steel support plate is trapezoidal. Two horizontally symmetrically placed steel support plates are combined to form a support component. A horizontal plate is symmetrically installed on the concave inclined surface of the steel support plate. A positioning protrusion is fixedly installed at one end of the steel support plate, and a positioning groove is opened at the other end of the steel support plate.

[0006] Supporting sliders are inserted into the gaps between the two horizontal plates in the same protective component. Square tubes are welded to the side walls of the two supporting sliders. A square block is inserted into the interior of each square tube. A positioning sleeve is welded between the two square blocks in the same protective component. A fixing component is installed inside the positioning sleeve. At least one positioning groove is opened on the top of the square block, and a pin is inserted into the interior of the positioning groove.

[0007] The fixing component includes a semi-circular insert block inserted into the inner wall of the positioning sleeve. The tops of the two semi-circular insert blocks in the same positioning sleeve are hinged to a fixing cylinder. A concave ring is welded to the outer wall of the fixing cylinder. A driving block is provided directly above the fixing cylinder. A C-shaped block is connected between the outer wall of the driving block and the concave ring. A tapered head is connected to the bottom outer wall of the two semi-circular insert blocks by thread engagement. A force-bearing rod is welded to the center of the top of the driving block.

[0008] Furthermore, the inner wall of the positioning sleeve is symmetrically provided with rectangular grooves, and the outer walls of the two semi-circular inserts are welded with rectangular strips, which are inserted into the rectangular grooves.

[0009] Furthermore, a reinforcing slider is inserted into the gap of the horizontal plate near the position directly below the supporting slider. A connecting block is welded to the center of the inner wall of the reinforcing slider. An arc-shaped groove is opened on one side of the connecting block. A positioning hole is opened in the lateral position of the arc-shaped groove. Fixing holes are opened near the bottom of both semi-circular inserts. The positioning hole and the fixing hole are limited by an insert rod.

[0010] Furthermore, a convex hole is provided at the center of the interior of the fixed cylinder, and a ball screw is centrally located inside the convex hole. The top of the ball screw is fixedly connected to the lower end face of the drive block. A movable slider is sleeved on the outer wall of the ball screw. A semi-circular groove is provided on the inner wall of the semi-circular insert. A support arm is hinged between the semi-circular groove and the outer wall of the movable slider. A limit groove is symmetrically provided in the vertical direction on the outer wall of the movable slider. A limit guide rail is inserted into the limit groove, and the top of the limit guide rail is welded to the lower end face of the fixed cylinder. A drive handwheel is fixedly installed on the top of the drive block.

[0011] Furthermore, a placement hole is provided in the center of the square block, a cross rod is inserted into the placement hole, and a support spring is provided between the cross rod and the placement hole. The end of the cross rod near the square tube is fixedly connected to the stop block.

[0012] Furthermore, the fixed cylinder has symmetrical mounting holes at its horizontal position, and one end of the mounting hole is connected to the convex hole. A guide rod and a pressing rod are respectively installed in the mounting hole, and a part of the pressing rod is sleeved on the outer wall of the guide rod. A return spring is installed between the guide rod and the pressing rod, and the end face of the pressing rod facing the convex hole is an inclined surface.

[0013] Furthermore, a support rod is fixedly connected to the top of the movable slider, and a pressing block is fixedly connected to the top of the support rod.

[0014] Furthermore, the top of the square tube is provided with rectangular holes, the number of which is the same as the number of positioning slots, and the rectangular holes are equipped with insertable rectangular blocks.

[0015] 1. The present invention provides a deep foundation pit excavation support structure for deep sandy soil, which is equipped with components such as support sliders. Before the steel support plate is constructed, the position of the steel support plate can be positioned by the cooperation between the support slider and the horizontal plate, and the cooperation between the positioning groove and the positioning protrusion. This ensures that the steel support plate always falls vertically when it is hammered by impact pile driving machinery, thus effectively ensuring that the steel support plate will not tilt during construction and ensuring the overall support effect.

[0016] 2: This invention provides a deep foundation pit excavation support structure for thick sandy soil. It includes fixed components and other parts. During steel support plate construction, the fixed components act as positioning devices to lock the position of the support sliders, ensuring that the support sliders do not shift during the hammering of the steel support plates, thus further guaranteeing the verticality of the steel support plates. During foundation pit excavation, rotating the drive handwheel causes the semi-circular inserts inside the fixed components to deflect, and the reinforcing sliders and support sliders provide multi-point internal support for the horizontal plates of the steel support plates, resulting in high overall stability of the steel support plate support. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram showing the connection status of several steel support plates of the present invention;

[0020] Figure 3 This is a schematic diagram of the working state of the present invention. Figure 1 ;

[0021] Figure 4 This is a schematic diagram of the working state of the present invention. Figure 2 ;

[0022] Figure 5 This is the present invention. Figure 1 A magnified view of a portion of region A in the middle;

[0023] Figure 6 This is the present invention. Figure 1 A magnified view of a portion of region B in the middle;

[0024] Figure 7 This is the present invention. Figure 4 A magnified view of a portion of region C in the middle;

[0025] Figure 8 This is the present invention. Figure 4 A magnified view of a portion of region D in the middle;

[0026] Figure 9 This is a partial structural schematic diagram of the fixing component of the present invention;

[0027] Figure 10 This is the present invention. Figure 3 A magnified view of a portion of region E in the middle;

[0028] In the diagram: 1. Steel support plate; 2. Support slider; 3. Square tube; 4. Square block; 5. Positioning sleeve; 6. Fixing component; 7. Positioning groove; 8. Pin; 9. Reinforcing slider; 11. Horizontal plate; 12. Positioning groove; 13. Positioning protrusion; 61. Semicircular insert; 62. Fixing cylinder; 63. Concave ring; 64. C-shaped block; 65. Drive block; 612. Conical head; 613. Rectangular strip; 651. Force rod; 652. Drive handwheel; 91. Connecting block; 92. Arc groove; 93. 94. Positioning hole; 95. Fixing hole; 66. Insert rod; 621. Convex hole; 622. Ball screw; 623. Moving slider; 624. Support arm; 625. Limiting groove; 626. Limiting guide rail; 627. Extrusion rod; 628. Guide rod; 629. Return spring; 620. Mounting hole; 41. Placement hole; 42. Cross rod; 43. Support spring; 44. Stop block; 6231. Support rod; 6232. Extrusion block; 680. Semicircular groove; 31. Rectangular hole; 32. Rectangular block. Implementation

[0029] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0030] like Figures 1-10As shown, the present invention discloses a deep foundation pit excavation support structure for deep sandy soil, comprising a steel support plate 1 for excavation support of deep foundation pits in deep sandy soil. The cross-section of the steel support plate 1 is trapezoidal. Two horizontally symmetrically placed steel support plates 1 are combined to form a support component. Horizontal plates 11 are symmetrically installed on the concave inclined surface of the steel support plate 1. A positioning protrusion 13 is fixedly installed at one end of the steel support plate 1, and a positioning groove 12 is provided at the other end of the steel support plate 1. During installation, multiple support components are positioned by interlocking. Specifically, after one support component is installed, a crane is used to align and insert the positioning protrusion 13 on one side of the steel support plate 1 with its adjacent positioning groove 12. The cooperation between the positioning protrusion 13 and the positioning groove 12 limits the horizontal movement between adjacent support components. The shape of the combined structure after interlocking can be seen in the figure. Figure 2 As shown;

[0031] Supporting sliders 2 are inserted into the gaps between the two horizontal plates 11 within the same support component. Square tubes 3 are welded to the side walls of the two supporting sliders 2. A square block 4 is inserted into the interior of each square tube 3. A positioning sleeve 5 is welded between the two square blocks 4 within the same support component. A fixing component 6 is installed inside the positioning sleeve 5. At least one positioning groove 7 is formed on the top of the square block 4, and a pin 8 is inserted into the interior of the positioning groove 7. Several positioning grooves 7 are evenly spaced. Taking the five positioning grooves 7 shown in the attached drawings as an example, the assembly formed by the square block 4 and the square tube 3 is placed horizontally on the surface of the sandy soil to be excavated. The square tube 3 is adjusted according to the actual pit width requirements. The placement of the square block 4 is adjusted as follows: The bottom of the square tube 3 is supported by the hand, causing it to move horizontally on the square block 4. The displacement distance between the two square tubes 3 on the same support component relative to the square block 4 should be consistent. Once the distance between the two support sliders 2 matches the width of the pit, the movement of the square tube 3 is stopped. The pin 8 is inserted into the positioning groove 7 close to the end face of the square block 4, locking the position of the square tube 3 with the pin 8 in the horizontal direction of the square tube 3 towards the fixing component 6. After the position of the square tube 3 is adjusted, the fixing component 6 can be installed. Multiple positioning grooves 7 can meet the needs of excavating pits of different widths.

[0032] See Figure 1 and Figure 3The fixing component 6 includes a semi-circular insert 61 inserted into the inner wall of the positioning sleeve 5. A fixing cylinder 62 is hinged to the top of two semi-circular inserts 61 within the same positioning sleeve 5. A concave ring 63 is welded to the outer wall of the fixing cylinder 62. A driving block 65 is positioned directly above the fixing cylinder 62. A C-shaped block 64 connects the outer wall of the driving block 65 to the concave ring 63. A conical head 612 is threadedly connected to the bottom outer wall of the two semi-circular inserts 61. A force-bearing rod 651 is welded to the center of the top of the driving block 65. In operation, after the position of the square tube 3 is adjusted, the conical head 612 is manually tightened to the bottom of the two semi-circular inserts 61, so that the two... The semicircular insert 61 is a single unit. Two semicircular inserts 61 are then inserted into the positioning sleeve 5. Under their own weight, the semicircular inserts 61 slide vertically down the positioning sleeve 5 until the conical head 612 falls onto the sandy soil surface. As the construction worker steps on the top of the square tube 3 and strikes the top of the force-bearing rod 651 with a hammer, the striking force is transmitted sequentially through the C-shaped block 64, the fixed cylinder 62, and the semicircular insert 61 to the conical head 612, causing the conical head 612 to penetrate into the sandy soil layer. The striking stops when the lower end of the C-shaped block 64 contacts the upper end of the positioning sleeve 5. In this state, the overall position of the fixing assembly 6 is as follows: Figure 3 As shown, the position of the support slider 2 is fixed by inserting the fixing component 6 deep into the sandy soil layer. After the position of the support slider 2 is fixed, the steel support plate 1 for support can be inserted along the support slider 2 by a crane. Then, the top of the steel support plate 1 is pressed by an impact pile driver. The impact pile driver can be one of a free fall hammer, steam hammer, air hammer, hydraulic hammer or diesel hammer. The steel support plate 1 for support can be inserted into the sandy soil to achieve the effect of excavation support. In this method, the lowering position of the steel support plate 1 can be limited by the support slider 2, so that the steel support plate 1 is inserted vertically into the sandy soil, effectively avoiding the tilting of the steel support plate 1 during the insertion process, and the support effect is better. After the steel support plate 1 is inserted into the sandy soil, the excavation operation can be carried out.

[0033] See Figure 1 The inner wall of the positioning sleeve 5 is symmetrically provided with rectangular grooves 51. The outer walls of the two semicircular inserts 61 are welded with rectangular strips 613, and the rectangular strips 613 are inserted into the rectangular grooves 51. When the force rod 651 is struck to make the semicircular inserts 61 and the conical head 612 enter the sandy soil, the rectangular strips 613 on the outer wall of the semicircular inserts 61 always slide down the rectangular grooves 51. That is, the cooperation between the rectangular strips 613 and the rectangular grooves 51 can prevent the semicircular inserts 61 from rotating during the sliding process. Under the restraint of the rectangular strips 613 and the rectangular grooves 51, the force rod 651 can also be pressured by the impact pile driving machine.

[0034] See Figure 1 , Figure 4 and Figure 6 A reinforcing slider 9 is inserted into the gap of the horizontal plate 11 near the lower part of the supporting slider 2. A connecting block 91 is welded to the center of the inner wall of the reinforcing slider 9. An arc-shaped groove 92 is opened on one side of the connecting block 91, and a positioning hole 93 is opened in the transverse position of the arc-shaped groove 92. A fixing hole 94 is opened near the bottom of each of the two semi-circular inserts 61. The positioning hole 93 and the fixing hole 94 are limited by a rod 95. In specific work, after the steel support plate 1 is inserted into the sandy soil, the foundation pit is excavated manually. When the excavation depth reaches the bottom horizontal position of the cone head 612, the cone head 612 is disassembled manually. Then, the two semi-circular inserts 61 are manually pried open. This causes one end of the semicircular insert 61 to deflect towards the steel support plate 1. Then, the sand and soil inside the steel support plate 1 are cleaned. The cleaning method can be shoveling. After cleaning, the two reinforcing sliders 9 are manually pushed down along the gap of the horizontal plate 11. When the reinforcing slider 9 moves to the point where the semicircular insert 61 deflects, one side of its end stops moving. Then, one end of the semicircular insert 61 is inserted into the arc groove 92. At this time, the positioning hole 93 and the fixing hole 94 coincide. Finally, the insert rod 95 is inserted into the positioning hole 93 to complete the positioning of the semicircular insert 61. This achieves a multi-point support effect on the inner side of the steel support plate 1, making the overall support of the steel support plate 1 more stable.

[0035] In another embodiment, see Figures 1-10A convex hole 621 is centrally located inside the fixed cylinder 62. A ball screw 622 is centrally located inside the convex hole 621, and the top of the ball screw 622 is fixedly connected to the lower end face of the drive block 65. A movable slider 623 is sleeved on the outer wall of the ball screw 622. A semi-circular groove 680 is formed on the inner wall of the semi-circular insert 61. A support arm 624 is hinged between the semi-circular groove 680 and the outer wall of the movable slider 623. A limit groove 625 is symmetrically formed vertically on the outer wall of the movable slider 623. A limit guide 626 is inserted into the limit groove 625, and the top of the limit guide 626 is welded to the lower end face of the fixed cylinder 62. The limit guide 626 is used to limit the movement of the slider. The cooperation between rail 626 and limiting groove 625 locks the circumferential position of movable slider 623 relative to ball screw 622. A placement hole 41 is centrally located inside the square block 4, and a cross rod 42 is inserted into the placement hole 41. A support spring 43 is provided between the cross rod 42 and the placement hole 41. One end of the cross rod 42 near the square tube 3 is fixedly connected to the stop block 44. Mounting holes 620 are symmetrically provided at the horizontal position of the fixed cylinder 62, and one end of the mounting hole 620 communicates with the convex hole 621. A guide rod 628 and a pressing rod 627 are respectively installed in the mounting holes 620, and a portion of the pressing rod 627 is sleeved on the guide rod 628. 8. A return spring 629 is installed between the guide rod 628 and the extrusion rod 627 on the outer wall. The end face of the extrusion rod 627 facing the convex hole 621 is inclined. A support rod 6231 is fixedly connected to the top of the movable slider 623. An extrusion block 6232 is fixedly connected to the top of the support rod 6231. A drive handwheel 652 is fixedly installed on the top of the drive block 65. A rectangular hole 31 is opened on the top of the square tube 3. The number of rectangular holes 31 is the same as the number of positioning slots 7. A rectangular block 32 that can be inserted is provided in the rectangular hole 31. In the initial state, the cross rod 42 is in the center position of the placement hole 41 under the extrusion of the support spring 43. One end of the bar 42 is flush with the inner wall of the positioning sleeve 5. Under the pressure of the return spring 629, the top of the pressing bar 627 is close to the connection between the guide bar 628 and the mounting hole 620. One end of the pressing bar 627 is flush with the end face of the rectangular bar 613. The support bar 6231 and the pressing block 6232 are respectively in the convex hole 621, or more precisely, in the gap between the convex hole 621 and the ball screw 622. The support bar 6231 and the pressing block 6232 are located directly below the pressing bar 627. When the lower end face of the C-shaped block 64 contacts the upper end face of the positioning sleeve 5, the cross bar 42 and the pressing bar 627 are in the same horizontal plane.In this embodiment, there is no need for manual manipulation of the semicircular insert 61. The construction worker can directly drive the drive block 65 to rotate via the drive handwheel 652. The rotating drive block 65 then drives the ball screw 622 to rotate. Since the circumferential position of the movable slider 623 is locked, that is, the movable slider 623 cannot rotate with the ball screw 622, the movable slider 623 will rise along the ball screw 622 during the rotation of the ball screw 622. After the movable slider 623 rises, it drives the support arm 624 to rise together. The other end of the support arm 624 will support the deflection of the semicircular insert 61. Then, one end of the semicircular insert 61 is fixed, for example; Figure 4 As shown in the scenario, this method eliminates the need for manual manipulation of the semicircular insert 61. The semicircular insert 61 can be quickly unfolded by rotating the drive handwheel 652, making it convenient and labor-saving. Before rotating the drive handwheel 652, the rectangular block 32 is inserted into the rectangular hole 31, ensuring one side wall of the rectangular block 32 is flush against the side wall of the stop block 44. Rotating the drive handwheel 652 moves the slider 623 upward, simultaneously raising the support rod 6231 and the pressing block 6232. When the semicircular insert 61 deflects into the arc-shaped groove 92, the inclined surface of the pressing block 6232 precisely presses against the inclined surface of the pressing rod 627. Figure 8 As shown, the extrusion force generates a horizontal thrust on the extrusion rod 627, causing the extrusion rod 627 to move toward the cross rod 42 and apply pressure to it. Under the action of the extrusion force, the cross rod 42 moves horizontally toward the rectangular block 32 along the placement hole 41 and applies extrusion force to it. The rectangular block 32 directly transmits the extrusion force to the horizontal plate 11 on the steel support plate 1, making the contact between the two steel support plates 1 in the same support component and the sandy soil more compact, further increasing the support stability of the steel support plate 1.

[0036] It should be noted that when the two semicircular inserts 61 are inserted into the inner wall of the positioning sleeve 5, the inner walls of the two semicircular inserts 61 are in contact with each other, that is, there will be no large gap between the two semicircular inserts 61. In this way, when the force rod 651 is applied to push the semicircular inserts 61 into the sandy soil in the early stage, the internal cavity between the two semicircular inserts 61, that is, the internal space of the semicircular groove 680, is in a closed state. The sand will not adhere to the ball screw 622 through the gap between the two semicircular inserts 61, and will not affect the use of the ball screw 622. The gap between the two semicircular inserts 61 that can be seen in the attached drawings is only to show the internal components of the semicircular groove 680.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A support structure for deep foundation pit excavation in deep sandy soil, comprising steel support plates (1) for excavating and supporting deep foundation pits in deep sandy soil, characterized in that, The cross section of the steel support plate (1) is trapezoidal. Two horizontally symmetrically placed steel support plates (1) are combined to form a support component. A horizontal plate (11) is symmetrically installed on the concave inclined surface of the steel support plate (1). A positioning protrusion (13) is fixedly installed at one end of the steel support plate (1), and a positioning groove (12) is opened at the other end of the steel support plate (1). Supporting sliders (2) are inserted into the gaps between the two horizontal plates (11) in the same protective component. Square tubes (3) are welded to the side walls of the two supporting sliders (2). A square block (4) is inserted into the interior of each square tube (3). A positioning sleeve (5) is welded between the two square blocks (4) in the same protective component. A fixing component (6) is installed inside the positioning sleeve (5). At least one positioning groove (7) is opened on the top of the square block (4), and a pin (8) is inserted into the interior of the positioning groove (7). The fixing component (6) includes a semi-circular insert (61) inserted into the inner wall of the positioning sleeve (5). The tops of the two semi-circular inserts (61) in the same positioning sleeve (5) are hinged to a fixing cylinder (62). A concave ring (63) is welded to the outer wall of the fixing cylinder (62). A driving block (65) is provided directly above the fixing cylinder (62). A C-shaped block (64) is connected between the outer wall of the driving block (65) and the concave ring (63). A tapered head (612) is connected to the bottom outer wall of the two semi-circular inserts (61) by threaded engagement. A force-bearing rod (651) is welded to the center of the top of the driving block (65). A reinforcing slider (9) is inserted into the gap of the horizontal plate (11) near the position directly below the supporting slider (2). A connecting block (91) is welded to the center of the inner wall of the reinforcing slider (9). An arc groove (92) is opened on one side of the connecting block (91). A positioning hole (93) is opened in the horizontal position of the arc groove (92). A fixing hole (94) is opened near the bottom of both semi-circular inserts (61). The positioning hole (93) and the fixing hole (94) are limited by a plug rod (95).

2. The deep foundation pit excavation support structure for deep sandy soil as described in claim 1, characterized in that... The inner wall of the positioning sleeve (5) is symmetrically provided with rectangular grooves (51), and the outer walls of the two semi-circular inserts (61) are welded with rectangular strips (613), and the rectangular strips (613) are inserted into the rectangular grooves (51).

3. The deep foundation pit excavation support structure for deep sandy soil as described in claim 1, characterized in that... A convex hole (621) is provided in the center of the interior of the fixed cylinder (62). A ball screw (622) is provided in the center of the convex hole (621). The top of the ball screw (622) is fixedly connected to the lower end face of the drive block (65). A movable slider (623) is sleeved on the outer wall of the ball screw (622). A semi-circular groove (680) is provided on the inner wall of the semi-circular insert (61). A support arm (624) is hinged between the semi-circular groove (680) and the outer wall of the movable slider (623). A limit groove (625) is symmetrically provided in the vertical direction on the outer wall of the movable slider (623). A limit guide rail (626) is inserted into the inside of the limit groove (625). The top of the limit guide rail (626) is welded to the lower end face of the fixed cylinder (62). A drive handwheel (652) is fixedly installed on the top of the drive block (65).

4. A deep foundation pit excavation support structure for deep sandy soil as described in claim 3, characterized in that... The square block (4) has a placement hole (41) in the center. A cross rod (42) is inserted into the placement hole (41), and a support spring (43) is provided between the cross rod (42) and the placement hole (41). The end of the cross rod (42) near the square tube (3) is fixedly connected to the stop block (44).

5. A deep foundation pit excavation support structure for deep sandy soil as described in claim 4, characterized in that, The fixed cylinder (62) has symmetrically opened mounting holes (620) at the horizontal position, and one end of the mounting hole (620) is connected to the convex hole (621). A guide rod (628) and a pressing rod (627) are respectively installed in the mounting hole (620), and a part of the pressing rod (627) is sleeved on the outer wall of the guide rod (628). A return spring (629) is installed between the guide rod (628) and the pressing rod (627), and the end face of the pressing rod (627) facing the convex hole (621) is an inclined surface.

6. A deep foundation pit excavation support structure for deep sandy soil as described in claim 4, characterized in that, The top of the movable slider (623) is fixedly connected to a support rod (6231), and the top of the support rod (6231) is fixedly connected to a pressing block (6232).

7. A deep foundation pit excavation support structure for deep sandy soil as described in claim 4, characterized in that, The top of the square tube (3) is provided with a rectangular hole (31). The number of rectangular holes (31) is the same as the number of positioning slots (7), and a rectangular block (32) that can be inserted is provided in the rectangular hole (31).

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